Thousands of people have been detained in Indian-controlled Kashmir over fears of outbreaks of unrest after the New Delhi government revoked the Muslim-majority Himalayan region’s autonomy.

An Indian government source speaking on the condition of anonymity said on Sunday that at least 4,000 people were held under the so-called Public Safety Act (PSA) since New Delhi stripped the restive region of its special autonomous status on August 5, AFP reported.

“Most of them were flown out of Kashmir because prisons here have run out of capacity, media outlets quoted the source as saying.

The source noted that he had used a satellite phone allocated to him to collate the figures from colleagues across the Himalayan territory.

A police official also said that “around 6,000 people were medically examined at a couple of places in Kashmir’s main city of Srinagar after they were detained.”

“They are first sent to the central jail in Srinagar and later flown out of here in military aircrafts,” he added

Authorities have repeatedly declined to provide a tally of how many people have been taken into custody over the past few weeks. They said the “few preventive detentions” were made to avoid a “breach of the peace” in the contested region.

On August 5, the administration of Indian Prime Minister Narendra Modi delivered a surprise executive decree to strip the Indian portion of the Muslim-majority Himalayan region of its special status. Modi has claimed that the decision was necessary for Kashmir’s economic development and would stop “terrorism.”

Fearing an angry and potentially violent response, India dispatched thousands of additional troops to the region, declared a strict curfew, shut down telecommunications and internet services, and arrested political leaders and pro-independence campaigners.

Thousands of people have been detained under the PSA, which allows imprisonment for up to two years without trial or charge, since the eruption of anti-India Insurgency three decades ago.

Authorities said earlier Sunday that more telephone exchanges would return to normal operations “by the evening.” Schools in some areas would reopen on Monday.

This came as Indian forces were gradually easing a massive movement and communications lockdown imposed two weeks ago.

Media reports, however, said people on Sunday were being turned back at multiple roadblocks set up in Srinagar, with security forces at some roadblocks telling residents there is a curfew.

India’s decision in Kashmir has sparked protests from the local population, outrage from Pakistan and unease from neighboring China.

Kashmir has been split between India and Pakistan since partition in 1947. Both countries claim all of Kashmir and have fought three wars over the territory. China also claims a part of the Ladakh region of the state of Jammu and Kashmir.

Indian troops are in constant clashes with armed groups seeking Kashmir’s independence or its merger with Pakistan.

In recent days, India and Pakistan have also exchanged heavy fire across the militarized de facto border in disputed Kashmir valley. India regularly accuses Pakistan of arming and training militants and allowing them cross the restive frontier in an attempt to launch attacks. Pakistan strongly denies the allegation.